Ground clamp



M5); 18, 1954 G. c. THOMAS, JR.. ET AL 2,679,032

GROUND CLAMP Filed June 7, 1951 lll/MAW :du: INVENToRS Garasa C. THoMns,JR.

THEIR ATTORNEY Patented May 18, 1954 GROUND CLAMP George C. Thomas, Jr., Elizabeth, and Walter H. Weber, Metuchen, N. J., assignors to The Thomas & Betts Co., Elizabeth, N. J., a corporation of New Jersey Application June 7, 1951, Serial No. 230,358

The invention relates in general to a connector for connecting two conductors in mechanical and electric relation, especially when disposed in parallel, spaced-apart relation, and, specifically, the invention relates to a ground clamp for connecting a ground wire, usually of small diameter, to a grounding conductor of very large diameter, usually a water pipe. More definitely identified, the invention relates to an improvement in pressure connectors of the water pipe type where both of the conductors are clamped simultaneously between a pair of pressure jaws by the action of a single screw bolt operative to squeeze the conductors between the jaws.

It is a commercial requirement of such connectors that they be made to accommodate pipes, wires and other conductors of different sizes, so that, irrespective of their relative sizes, of course Within the capacity of any one set of sizes of connector, a rm and extensive electrical and mechanical engagement be provided between the connector and both of the selected conductors. While such connectors as now known can be designed to fit any one particular size of either of the two conductors, they have not been designed with the intent of providing a fashion-fit to both conductors and at the same time made rigid in order to eliminate springing or other deformation of the clamping structure. In general, particularly considered from an economic standpoint, while such connectors must be made compact and rugged, they must also be designed with l,the use of the least possible amount of the ex- -pensive conductive metal necessary in such devices to function efficiently; the component parts should be few in number, preferably as castings designed to be easily manufactured, free of expensive machining, and easily and quickly installed in place on various size conductors even by unskilled labor.

The primary object of the invention is to provide a connector of the clamp type above outlined, which will be free of the objections heretofore raised against known forms of similar devices and which will at the same time respond to the above-outlined commercial requirements.

Still another object of the invention incidental to the objective of providing a compact form of connector is to streamline the same in order to eliminate as far as possible flanges and like extensions which if struck accidentally might result in enough deformation to loosen the contact pressure on one or both of the conductors.

The disclosure particularly features a form of clamp, the jaw-forming elements of which are 13 claims. (o1. sse-246) simple bronze castings which effect a minimizing in the amount of material used compared to known forms of similar clamps and wherein the material, while limited in its mass or weight, is apportioned to strengthen those parts which are most liable to be subjected to rupturing strains and to provide for mutual reinforcing of adjacent parts, leaving the cross section of material therein unreiniorced in the parts where such strains are least liable to occur.

The pipe-engaging parts of the jaw members of` the embodiment of the invention herein disclosed feature a form of clamp which provides for at least a four-point contact with the pipe, two points for each jaw engaging the pipe, irrespective of small variations in its diameter, and which, while providing the necessary area of electric contact required of such devices, will minimize any possibility of crushing the pipe, especially when the pipe is relatively frail, as when made of thin gauge copper tubing.

Another object of the invention is to provide in a single pair of jaws a disposition of contact teeth which will form circumferentially spacedapart contact points around the circumference of different sizes of conductors to direct squeeze forces on any size for the time being in place in balanced relation along lines substantially at right angles to each other and passing through the axis of the conductor engaged thereby.

Various other objects and advantages of the invention Will be in part obvious from an inspection of the accompanying drawings and in part will be more fully set forth in the following particular description of two forms of device embodying the invention, and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawings,

Fig. 1 is a perspective view of a water pipe clamp constituting a preferred embodiment of the invention, showing a cable clamping extension, with a pair of conductors, specifically, a thin wall water pipe and an armoured ground wire, clamped thereby, with the conductors shown in ghost outline and with the ground wire shown solid.

Fig. 2 is a plan view of the clamp shown in Fig. 1, with the conductors omitted and with the top member partially broken away to show in plan the lower groove of small radius.

Figs. 3-6 are views in side elevation of a modified form of clamp with the cable clamping extension of Figs. 1 and 2 removed to show the jawforming parts in side elevation as viewed from the line 3 3 of Fig. 2; Fig. 3 being an explanatory view of the tooth arrangement; Fig. 4 showing the jaws engaging a small diametered rod in place of a pipe; Fig. 5 showing the jaws engaging a medium size water pipe; and Fig. 6 showing the jaws engaging a large size water pipe.

In the drawings there is shown a ground clamp l5 formed solely of three separately formed parts factory-assembled to form a unitary article of manufacture. Two of the parts II and I2 are rugged bronze castings and the third part is a steel screw bolt i3 oi standard design available for purchase on the open market. One of the parts ll"will`bereferredto hereinafter as a body, and the other part I2 as a cap. Y

In the illustrated showing, the body is the upper of the two parts and is provided on oneside with an integral and lateral extension i4 which may be omitted when its function is not desired. The clamp will rst be described, ignoring this extension and thus describing a simplified form of clamp particularly designed for use with a bare ground wire instead of the shielded cable shown in Fig. l. The part of the body, except the extension, forms an upper jaw-forming member l5 and all of the cap I2 forms a lower jaw-forming member. The jaw members I2 and I are of greater length thanv i.

width, are of somewhat similar configuration, and each is arched slightly in side elevation with the concaved sides lacing each other. The jaw members are each of the same material width as viewed in plan in Fig. 2 and are of comparai T tively small cross section of material except at their long marginal edges hereinafter described. The inner side of each jaw member which faces the other is provided at oneend with a transversely extending concave recess iii of relatively large radius, and at the other end with a transversely-extending concave recess li of quite small radius. The large recesses l5 of the two jaw members are in opposing relation and are designed to accommodate therebetween a conductor of large diameter,such asI the pipe P or rod R'. Similarly, the recesses il of small radius are in opposing relation and designed to accommodate therebetween aground wire W of small size. In the illustrated case the j aw` members are each about one and three-quarter inches long, and eleven-sixteenths inch wide; the pipe P (Fig. 5) is a half-inch copper tubing water pipe, but the clamp is designed so that it can equally take a small rod (Fig. 4) or a threequarter inch pipe as shownin Fig. 6. The wire W illustrated is number '4, but the clamp can equally take a number 6 orl 8 size wire.

Qpposite ends of the jaw members I2 and- I5 are provided withloose interlccls which tend to restrain relative lateral shifting of the jaw members when in their conductor-clamping position and at the same time permit relative adjustment of the jaw members in the direction of their clamping movement to permit them to lit the conductors for the time being'in use. For this purpose the opposite ends of the jaw member I5 are each bifurcated to form' slots for receiving lugs formed as extensions from the jawforming member I2. More specifically described, the end of member I5 which has the large recess I6 is formed of a pair of long, hook-like bifurcations i8 curved in side elevation and forming a long slot I9 therebetween. Similarly, the end of member I5 which has the recess ofsmall 4 radius is formed of a pair of relatively short bi'- furcations 2Q forming therebetween a short slot 2l.

The jaw member I2 is provided at one end with a long, narrow lug 22 curved in side elevation, forming an extension in. prolongation of the member I2 and loosely extending into` the long slot Iii when the pipe P is of sufficiently small radius to permit such intrusion as shown in Fig. 4. In those cases where the pipe is large the lug 22 is apt to be entirely outside of the slot I9 as shown in Figs. 5 and 6. Similarly, the jaw member I2 is provided at its other end with a lug 23, shorter than the lug 22, in prolongation of the member l2v and extending into the slot 2I.

The deep recessie in the member I5 is formed partly in the lower face of the two bifurcations I3 and partly in the adjacent inner portion of the lower face of the member I5 up to the bolt I3. The deep recess I6 in the member I2 is formed partly in the upper face or". the 1ug122 and partly in the adjacent inner portion ofthe upper face of the member I2 up to the'bolt I3.

The recess I'I in the member I2is formed at the base of the lug 23. The lu'g 23 acesfand sometimes extends into the slot ZI in such way that with the wire W in place and when a squeeze load is imposed on the jaw members the lug 23 tends to snub or slightly bend the part offthe' wire which is bridged across the slot2^l formed'i between the pair of bifurcations 2U.

The lower jaw member I2 is provided at opposite edges with a pair of" depending marginali flanges 24 of relatively small depth, each of which extends along the sidesof `the long lug 22 and along the member I2 to a thick portion 25 adjacent the associated recess Il; The struc' ture between the longing 22 and the thickened portion .forms in effect a wide web 26 with marginal flanges which tend to reinforce the relatively thin web against bending strains. Simi` larly, the upper jaw member i5 isprovided along its opposite edges with a pair of upstanding, marginal reinforcing flanges 2T which extend along the outer edges of bifurcations!!! to a thickened portion 28 of the member I5 adjacentthe'asso# ciated recess II. The member I5 is alsoprovided at its opposite edges and between the-recesses I 6 and il witha pair of depending, .integral, marginal flanges 29 which tend to provide additional reinforcement in' the short leverforming part of member I5 between the line*v ofthrust provided by the-bolt I3 and the small recess I?. This structure likewise provides in the region ofv the bolt I3 aweb 30 reinforced at its edges by flanges 21 and 29.y The outer1l side faces of flanges 2li are provided with V` shaped pockets 3-I for receiving the lower pointed-- ends 32 of the depending iianges 29 to resistf relative transverse movement of4 the jawswhen': the flanges 24 and 2'I are in lapping relation as shown in Figs. 4 and 5.

' The somewhat iiat portions `of the webs 26 and 3i] which'lie between the recesses I5 and Il are provided, respectively, with aligned boltholesy 33V and 34. These bolt holesl are elongated in* the direction lengthwise of their associatedjaw members.

-The screw bolt I3, which initheillustrated case is aboutone and one-half inches long;-is passed loosely through thealignedbolt holes; The bolt includes a threaded shank 35 provided with a head 36 and a square `nut 3l' bearing respectively on thewebs ofthe members I2` and l5. l The. nutis..held-,fromzrotatine withitheshank.

by reason of its loose nt between whichever of the marginal flanges 24 or 21 it may happen to be contained. The lower end of the bolt shank is peened after it is installed to provide a captive bolt and in this way defeat possibility of the parts becoming permanently separated.

The outer portions of jaw members I2 and I5 which outline, respectively, the bolt holes 33 and 34 form pressure seats 38 and 39 for engagement by the at under sides of either the head 36 or the nut 3l. These pressure seats are formed between their associated marginal flanges and are arched outwardly and longitudinally with the outermost lines or crowns of the arches of each member in transverse alignment to provide a line-like form of pressure seat for each member. By this means and regardless of the size of wire or pipe clamped, and thus regardless of Whatever angle to the jaw members may be assumed by the bolt, the screw head and the nut each always rests on the pressure seats of the jaw members at or near, respectively, the screw head or the nut center. Particularly in the case of the screw head the contact along a radial line through the center of the head is much more efficient and provides a better clamping pressure with the various inclinations of the bolt than would be the case if the screw head contacted only at one edge of a flat pressure seat.

The recesses I6 which are fashioned for engagement with the pipe P or rod R are preferably serrated in a novel way. In the form illustrated each recess I6 is curved on a double radius and is otherwise designed to provide a lit on pipes or rods having different diameters and to contact either a large size or a small size conductor along at least four lines, two on each jaw member.

Each member is provided at its recess I6 with two sets of transversely extending teeth with one set separated from the other by a wide, transversely extending groove 40. The teeth which form the outer set 4I and which are contained partly in the inner faces of the long bifurcations I8 and in the inner face of the associated long lug 22 and partly in the adjacent part of the inner faces, have their tooth ridges or points 42 in the arcs of a circle of relatively short radius R' and struck from a. center on the axis ab, bisecting the opening between the jaws and passing through the center of the wire W as shown in Fig. 3.

The teeth which form inner set 43 which lies in the inner faces of the jaw members I2 and I5 close to the bolt I3 have their ridges or points 44 each in the arcs of circles of relatively longer radius R2 and struck on arcs whose centers C are also on the axis aF-b, but spaced a short distance outwardly from the center of C as shown in Fig. 3.

In the illustrated case the upper jaw has five teeth in the set 4I, designated from left to right as a, b, c, d, and e, while the lower jaw has six teeth designated as a', b', c', d', e', and f'. The set 43 has in both the upper and lower jaws two teeth designated, respectively, g, h and g', h'.

Where the pipe is extremely large, say, slightly larger than the showing in Fig. 6, it is possible that the portion of the bolt which bridges across the space between the jaw elements will form a stop for limiting the lateral movement of the pipe in the direction towards the conductor W. These pitch circles are each considered as in the longitudinal, medial plane of the jaw members when in clamping position.

As to which teeth engage the conductors there-1 in depends upon the diameter of the large conductor for the time beingr clamped by the jaws. In all cases at least two points of each jaw, or a total of four points, engage the large conclue-l tor. The small rod R (Fig. 4) which has a diameter substantially equal to the radius R is engaged by the four teeth on opposite sides of the recess 40, to-wit, teeth e and g of the upper jaw and f and g of the lower jaw. This means that the bearing points of the engaging teeth are grouped about the center of the rod R approximately 90 degrees apart, thus equally spaced apart, two on each of the opposing sides of the rod R. In the case of the medium size pipe (Fig. 5) six points are employed, to-wit, c, d and h of the upper jaw and d', e and h of the lower jaw. In this case, the bearing points h and h of the engaging teeth are spaced about 90 degrees apart and the mean average spacing of the other bearing points of the set 4I therefrom is approximately 90 degrees, so that, here again, the bearing points are more or less equally spaced apart. at least two on each side of the axis a-b passing through the center of the pipe P. The points not mentioned in each case are spaced outwardly clear of the adjacent portion of the perimeter o1" the pipe or rod.

In the case of the larger size D (Fig. 6), nine points, to-wit, a, b, c and h of the upper jaw and a', b', c', d and h of the lower jaw, bear on the pipe P. In this case, as in Fig. 5, the bearing peints b and h are circularly spaced about 90 degrees apart and diametrically opposite each of these points two or more teeth bear on the pipe so that, here again, the contact points are at least substantially spaced 90 degrees apart.

It is thus seen that, irrespective of the diam- I eters of the pip-e or rod for the time being in place,

the points of contact of the teeth are at least two on each jaw and the perimeter is engaged at four more or less equally spaced-apart points. In this way the same clamp can be used for widely different sizes of pipes.

In operation and assuming that the nut has been retracted sufficiently to permit the jaw members to separate from or to hang loose on the bolt, the jaw members are slipped over the pipe or rod and located to bring the same into the space between the large recesses IE. The bolt is advanced partly towards its clamping position at least sufficient temporarily to hold the clamp loosely on the pipe. An end of the wire W is then inserted endwise into the space formed between the smaller recesses I'I. At this time, the jaw members are free to rock on the pipe as a fulcrum and thus separate the recesses I1 sufciently to pass the wire W therebetween. When the clamp jaws are moved towards each other, even manually, they will tend to adjust themselves to at least an approximate fit with both the pipe and wire. By means of a screw driver the slotted head is rotated until the squeeze pressure imposed by bolt I3 firmly binds the clamp I0 first on one and the-n on the other of the conductors P and W. The squeeze pressure is apportioned largely on the wire W by reason of the relatively short length of leverage effort between the line of thrust Z-t of the bolt and the center of the wire W. The proportionate lesser pressure is provided by reason of the relatively long length of leverage between the line of thrust and the center of the pipe P, but in any case this is sufcient to grip the pipe rmly without deforming 71 it-even though. it: may', be.. made cf` thin gauge copper.-

Reverting to thelateral/ extension Miwhich,

with thebasic parts :previously described, may be` consideredqasanother embodiment of the invention, this form is particularly designed for l use where the wird W, either of the solid or stranded' type, Vis contained in either a metal` shield iS or` a covering of insulatingmaterial;

The.; extension I4 is a hollow cylindricaltube whose;1 bore 45.is dimensioned sufficiently large. toareceivertheshield when cut back tol expose thegnakedlendofwire W. The bore 45 is coaxial with the'center oi the'wire-clamping space providedby the opposing recesses Il and at itsinnerv end forms an annular'stop wall Mthrough which the bare wire extends. screw 4l' is threaded through a side of the extension I4 to engage the shield S or the insulating covering therein whenv in end-abutting ena thenythe bolt I3 ,tightened as previously described.

1.A Ina device of the class described, the combination o1" a pair` of jawforming members havngf at` one vend of the device opposing free ends and at its other end provided with means for clamping a ground wire, one oi the members being bifurcated at its` free end to form a slot and side facing the other member with a transverse concave recess contained at least in part in the bifurcated end, and the free end of the, other memberv which has the lug provided with a concave recess contained at least in part in the lug, said recesses being in opposition to each other and fashioned for receiving therebetween conductors of different diameters, said recesses beingformed as two arcs of circles considered in themedal longitudinal plane of the jaw mem-` bers land said recesses being oi different radii, the are ofthe circle in that` part of the recess which is in the bifurcated end and in the lug having a .radius slightlysmaller than the circle whose arc defines the parts of the recesses remote from the free ends.

2. Inf a device of the class described, the cornbination of two jaw-forming members, each provided in the side facing the other with two transversely extending concave recesses, one of larger radius than the other, the recesses of larger ran dius facing each other to receive therebetween a conductor of large diameter and the recesses of smaller radius facing each other to receive therebetween a conductor of small diameter, the members provided with aligned bolt holes each elongated in the direction of the lengths of its associated member and located nearer the recess of smaller radius than the recess of larger radius, and a screw bolt passed loosely through the boltfholes for clamping the members onto con- A steel binding ductors located in said recesses, the recesses of the two sets apart, the points. of the 'teeth of -each.`

set located-inthe arcsof two circles bothv considered inthe longitudinal medial plane of the jaw members, `the points ofthe .teeth forming the set. nearest the screw bolt being in the arc of4 a circle having a slightly larger diameter thanthe arc of the circle which contains the points of the teeth` of the setatthe free-outer part of the.

jaw members remote from thescrew bolt.

3, A` clamp forclutching pipes of diiierent externalzdiamcters and including two jaws pivotally related; at one end, each of said' jaws provided adjacent its other end with a concaved recess, and the two recesses disposed with their` concaved sides in opposing relation and coacting tofclampa pipe therebetween, a bolt located between the pivoted ends andthe recesses for extending a squeeze loadV on the jaws, each of said concavedrecesses provided with transversely dis- ...posed teeth of V-form disposed in parallel relation, arranged: in two sets with a blank groove therebetween, the points of the teeth of the set nearest the bolt defining an arc of a circle of large radius `and the points of the teeth ofthe 1. other set being more than three equidistantly spaced apart and` deiining an are of a circle of relatively smaller radius.

4. A clamp for clutching conductors of different external diameter, including a pairV of co.

i acting jaws, means at one end of the clamp for pivotally connecting the jaws, said jaws having opposingconcaved recesses at their other end for i receiving therein conductors of different diameters, said opposing recesses being on opposite sidesyofigan axis extending through the pivotal connection, each recess provided. centrally thereof with a concaved groove and on opposite sides thereof with two sets of parallel transversely extending V-teeth, the ,points of the teeth of one setbeing tangent to the arc of a circle of relatively large radius and whose center is in said axis, and the points of the teeth of the other set being tangent to the arc of a circle of relatively smaller radius and whose center is in said axis, the number of teeth tangent to the arc of smaller rad-ius being greater than the number of teethy tangent toy the arc of larger radius, and a screw bolt foracting on the jaws, said boltl being dise posedadjacent said axis and nearer the set of teeth ofsmaller number than the vteeth of greater number.

5. A jaw clamp including a pair of pivotally=connected at one end, each having a recess ingits work face` adjacent its other endeach of said recesses defined by a plurality of V-teeth disposed in parallel relation transversely of the length of the jaw and arranged in two sets, the teeth forming the s et adjacent said end being morethan three in number and having therein points tangent to the arc of a circle of relatively concave recess,` ,eachof said recesses provided centrally thereof with a concave groove and on opposite sides thereof with two; sets .ofgparallel 9 transversely' ,extending teeth, the teeth of the set nearest the pivotal connection in both jaws being two in number and tangent to a circle whose cen-- ter lies in an axis located between the jaws passing through the pivotal connection. the teeth of the other set on one of the jaws being five in number, and the teeth of the other set on the other jaw being six in number, and with both the ive and six toothed sets tangent to a circle whose center is also on said axis and whose radius is shorter than the radius of the circle to which the two toothed set is tangent and with the teeth of each set equidistantly spaced apart.

7. A clamp of the pressure type for mechanically and eiectrically connecting a small diametered wire to a conductor of relatively large dialneter, including two jaws formed ci highly conductive metal arcuate in side elevation and provided at opposite ends with a projection from the end of one jaw located in a slot formed in the adjacent end of the other jaw to provide loose interlocks at opposite ends of the clamp, each jaw comprising a long, narrow arcuate web provided at one end with a pair of outwardly pro jecting marginal flanges, the jaws forming therebetween at said end a recess of relatively large diameter for receiving the large conductor, the jaws at their other ends being each of greater thickness of material and thus more rugged than the iirst-named ends of the jaws, said ends of greater thickness provided with aligned bolt holes in part formed in that part of the web which deines the large diametered recess, the deep por tion of each jaw on opposite sides of its associated bolt hole forming deep, inwardly projecting marginal flanges in part dening said ends or" greater thickness, with the flanges of one jaw lapping the flanges of the other jaw to resist relan tive lateral movement when the flanges are in lapping relation, and said jaws in their region of greatest thickness and adjacent the contiguous end interlock provided with registering recesses of relatively small diameter forming a space for receiving the wire, and a single bolt passed through the bolt holes, located between the recesses of large and small diameter and located close to the registering recesses of small diameter for squeezing the jaws into engagement with the conductor and the wire.

8. The clamp defined in claim '7, wherein the outer sides of the flanges of one of the jaws are provided on opposite sides of the associated bolt hole with a pair of inwardly-facing pockets and the iianges oi' the other jaw are each provided with a pointed end, with the pointed ends adapted to be received in the pockets when the flanges are in lapping relation and operative in close proximity to the bolt to supplement the end interlocks to resist relative transverse movement between the jaws.

9. The clamp dened in claim '7, wherein the bolt holes are elongated in the direction of the length oi the jaws and are located between the flanges, and wherein the outer faces of the webs in the portions thereof which outline the bolt hole provide elongated pressure seats for receiving squeeze pressure from the bolt and which seats lap the thick portions in which the recesses of small diameter are located, and a non-circular nut on the bolt located betwen the flanges oi one of the jaws, said nut being of greater dimension in one diametral direction than the distance between said ilanges and held thereby from rotating with the bolt.

10. The clamp dened in claim 7, wherein the webs in the parts which form the pressure seats vare each arched outwardly and longitudinally ywith the outermost crowns of the arches in mutual transverse alignment to provide a line-like form of contact on the pressure seat oi each jaw adapted to be engaged by either the head or nut of the bolt in the bolt holes.

, 1l. A clamp including two long, narrow jaws in superposed relation and provided at opposite ends with loose interlocks each operative to prevent ,relative transverse movement of the jaws,

the jaws at one end of the clamp being arcuate, vof relatively least thickness of material and with their concave sides facing each other and forming therebetween a recess of relatively large cross section, each of the jaws increasing in thickness oi material from said least thickness towards a maximum thickness adjacent its other end, the material of each jaw being massed largely in the part forming said other end thereby to give increased strength to said other end, the inner faces of said other ends at their extreme free ends provided with small opposing channels coacting to form a recess of relatively small cross section, said jaws provided with aligned bolt holes located mainly in the ends of said massed material, and a single bolt passed loosely through the vbolt holes for drawing the jaws towards each other and said bolt in the portion thereof which lies between the jaws being exposed to the recesses of both the large and small diameter and thus operative to denne and limit the adjacent ends of said recesses.

12. A clamp for electrically and mechanically connecting a small diametered wire to conductors of relatively large diameters and of different sizes, including two opposing long arcuate jaws of somewhat similar configuration provided at opposite ends with a projection from the end of one jaw adapted to be located in a slot formed in the adjacent end of the other jaw to provide loose interlocks at opposite ends of the clamp, each interlock operative when its projection is within its slot to resist transverse shifting of the associated end of the jaws, the jaws at one end of the clamp provided with opposing recesses of relatively large diameter for receiving therebetween a relatively large conductor and said jaws at their other end provided with opposing wirereceiving recesses of relatively small diameter, said jaws provided in the parts thereof which lie between the recesses with a projection from one in opposition to a recess in the other and said recess fashioned to receive the projection and said projection and recess coacting when in lapping relation to resist relative transverse shifting of the jaws, and a screw bolt passed loosely through the jaws adjacent said projection and recess to force the jaws towards each other.

13. Aconnector for use in mechanically and electrically connecting' two conductors, one of relatively large size and the other of relatively small size, comprising three separate parts, two of the parts being of highly conductive metal and forming a pair of coacting jaw members free of each other for relative adjustment, and the third part forming a connecting screw bolt, the jaw members being each of arcuate form in side elevation, each jaw member provided at one end thereof and on the side thereof facing the other member with a transversely extending concave recess, with the recesses facing each other and providing a space therebetween for receiving the larger of the two conductors, the opposing concave faces of said recesses being each provided 1l with two sets of teeth extending transversely of its associated member, with thesets spaced apart and operative for gripping said larger conductor at two circumferentialy spaced-apart points,and each jaw member provided. at its other end with a relatively small recess and with said'small 'recesses coacting in opposing relation to `receive therebetween the conductor of relatively small size, one of the jaw members provided at opposite ends thereof with a lug projecting therefrom, the other jaw member having its ends bifurcated to form slots, each slot adapted to receive its associated lug to form a loose interlock at each end of the connector, both jaw members provided at the end which has the larger recess with an out- 15 standing marginal reinforcing flange which `ex tends on one of thejawvmembers to theendof the associated lug and on the other jaw member to the ends of its associated bifurcated portion, each jaw member provided at the end of the `connector with the small recesses with a ange from one projecting inwardly towards a flange ofthe other, one of said flanges terminating in a lower pointed end adaptedto be received in a vpocket formed on one side of the otherange and said pointed end and pocket operative to resist transverseshifting-of thejaw members, and saidjaw members provided inthe part thereof which lies between the two conductor-receiving,recessesand ladjacentsaid vpocket andpointed end `andipartly Ynesting-screw ',boltjjpasses, and said outstanding flanges of eachjaw member adapted to receive therebetween a' nutonl the bolt and operative'to resist rotation of the nut with 'the bolt.

:References Cited inthe 'file of* this patent UNITED STATES `vPATEN TS Number fName "Date v902,040 yWyckoff Oct. g 27, y221908 1,943,020 `Johnson Jan.`9, l1934 :2,114,014 Church, Apn 12, 1938 2,116,474 Bonderson :May 3,"1938 .2,137,840 -,Hayesy Nov.;22, 1938 2,200,380 `:Bodendieck MayA 14, 19.40 2,509,082 Bodendieck, .LMaYU-213,v 11950 2,559,187 Clapp July, :1951 .2,651,766 -v-Rundef fsept.f8, 1953 lFOREIGN PATENTS Number `-Country Date )483,225 Germany -...,..Sept. -2f7, 1929 669,158 France J.u1y 27, i1\929 

